Enhanced CO<inf>2</inf> Photoconversion at Elevated Pressures Using Conductive Polymer Modified Metal–Organic Framework

Artificial photosynthesis is considered to be a promising approach for energy storage and global warming mitigation. However, the suboptimal selectivity of products and the low conversion efficiency of CO2 persist as challenges, driving continuous interest in improving catalytic design. Herein, a metal–organic framework (MOF) modified with a conductive polymer was constructed. The resulting composite, named TiFe-BTC/PoPD (BTC: 1,3,5-benzenetricar-boxylate; PoPD: poly-o-phenylenediamine), served as a highly efficient and selective photocatalyst for the conversion of CO2 to CO under visible light. Interestingly, thanks to the synergistic promotion of pressure and conductive polymer, the TiFe-BTC/ PoPD achieved a remarkable CO evolution rate of 7.178 mmol/g/h and demonstrated excellent selectivity of over 99% for CO at 6.0 MPa CO2. Thus, this approach resulted in ∼70-fold increase in the evolution rate compared with that of TiFe-BTC at ambient pressure (0.1 MPa). Experimental characterizations, combined with theoretical calculations further revealed that high-pressure CO2 effectively suppressed H2 evolution, thereby enhancing CO production and promoting high selectivity. This finding illustrated a straightforward strategy for an efficient photoconversion of CO2 to CO by subtly leveraging the synergistic effect of high-pressure CO2 and polymer-modified MOF photocatalyst.